Gundam Wing: Episode Zero is a series of short comics put out as inserts in the magazine "Anime V". The series presents an episode from each character's past - Relena, Duo, Heero, Quatre, Trowa, and Wufei (in that order). The glimpses into the characters' past offer an explanation for events in the series, and the characters reasoning for joining the war. While all these chapters are official, they're technically not canon and thus under constant discussion among GW fans. Especially Trowa's part is controversial - is Catherine really his sister, and does the Episode Zero prove it or not? The tankoubon version of Episode Zero also includes a story that take place after the end of endless waltz: Preventer 5.
